Magnetohydrodynamics (MHD) (magnetofluiddynamics or hydromagnetics) is the scientific discipline that studies the dynamics of electrically conducting fluids under the effect of magnetic fields. MHD is derived from “magneto” meaning magnetic field, and “hydro” meaning liquid, and “dynamics” meaning movement or motion. The field of MHD was initiated by Hennes Alfvén in 1942, for which he received the Nobel Prize in Physics in 1970.
The idea of MHD is that magnetic fields can induce currents in a moving electrically-conductive fluid, which create mechanical forces on the fluid, and also change the magnetic field itself. The set of equations which describe MHD are a combination of the familiar Navier-Stokes equations of fluid dynamics and Maxwell's equations of electromagnetism. Research studies indicate that magnetohydrodynamic effects are responsible for the magnetic treatment of fluids and gases.
All previous applications of magnetic treatment of fluids and gases focused on the direct application of magnetic or electromagnetic fields of various flux densities and variable geometries on the moving fluid or gas, where the entire or the totality of the fluid or gas should pass directly through the magnetic or the electromagnetic field in order to be treated. This direct treatment fact is the hidden obstacle for the limited popularity of the magnetic treatment since it leads to effective treatment only in the initial phases of installation of magnetic treatment devices, and generally ineffective treatment in the later stages.